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S. R. MERLEY ALCOHOL RECOVERY Filed Sept. 50, 1930 ...Illillllx vwewtozSYLVAN R. Maman' WMM Patented Aug. 23, 1932 UNITED STATES PATENnol-*FicSYL'VAN R. MEBLEY,0F DOVER, NEW JERSEY, ASSIG'NOB T0 RESEARCH C0!-AlP-ANY, OI' 'NEW'.YOBI, FLY., A CORPORATION' 0F DELAWARE 4 Leonornncovnnr appneatiop mea september ao, 1930. serial 110.485,401.

This invention relates to an improved process for recovering secondaryalcohols from a mixture of hydrolyzed alkyl sulfatos.

In the'art of cracking and refining petro-` l 5` leum oils, much ofthestill roducts formed.v

by such process contain olehns. To recover these ole ns they areabsorbed bya solution of a mineral acid, suchV as sulfuric acid. Thechemical reaction involved in the absorption f1', of these olefins bysulfuric acid resultsin the formation of alkyl sulfates.

The alkyl sulfates are then hydrolyzed with water under denitelcontrolled conditions, in the proportion ofy about one part of the alkylsulfates to four parts b weight of p water to produce a mixture osecondary alcohols and sulfuric acid. Since-the olefin, containingproducts obtained from petroleum refining and cracking contain variousamounts of ethylene, propylene, butylene,

amylene and hi erA olenns, they become saturated or este ed whencombined with sulfuric acid, and when they are hydrolyzed the alcoholsformed will containalkyl radicals correspondin to theradicals .of suchesters. As a result, erefore, a mixture of alcohols of varied carboncontent are obtained b the hydrolysis of corresponding alkyl sul ates.It is desirable, therefore, to se arate the 13o alcohols' from thehydrolyzed so ution and also'to separate the 4alcohols fromeach other.

An object of this invention is to provide a process for .separatingsecondary alcohols from avhydrolyzed mixture of alkyl sulfates and fromeach other without decomposition of such alcohols.

invention is that when the secondary alcoholsl lare obtained, there aresome alcohols, namely the isobutyl and lower alcohols, which are watersoluble, whereas the am l and higher alcohols are practically insolu le.e

A further object of this invention therefore is to separatewater-soluble butyl and lower alcohols, i. e., those of less than 4lcarbon content, from' the practically insoluble amyl and higheralcohols, i. e., those of more than 5 carbon content., Another object ofthis invention is to se i0 irate 4secondary butyl and lower alcohcs fromamyl and higher alcohols, obtained by the hydrolysis lof alkyl sulfates,by fractionating these alcohols under definitely conn trolled distillingconditions.

With these and other objects in view, the

invention will be best understood from the following detaileddescription'taken in connection with the accompanying drawing in which:

The figure is a diagrammatic flow sheet of the improved process.

` Referring tothe drawing, the hydrolyzed solution'of alkyl sulfatos tobe treated is introduced through a valve controlled pipe, 2,

into the upper portion of a column still, 4.

rlhe column still is of ordinary bubbler tray construction adapted forthe proper separation of the vapors from the liquids intro'- ducedthereinto. Live steam is introduced into the base of the column througha valve controlled pipe, 6, thus insuring .complete hydrolysis of thealkyl sulfatos. The steam also carries upward through the column thealcohol vapors formed. T he column still, 4, is heated by means of aclosed steam coil, 8,

'located at the base of the column and 'at a point below the live steaminlet, in order to provide sufficient heat to steam distill the varioussecondary alcohols resulting from the introduced mixtureof hydrolyzedalkyl sulfates. This closed steam coil supplies suficient heat to keepthe alcohols present therein in vapor phase.

TheV hydrolyzed solution of alkyl 'sulfates contains besides, alcohols,and sulfuric acid,

1- fsome polymers, hydrogen sullide, sulfur di- With this object inview, a feature of this'f pui-ities from the hydrolyzed alkyl sulfatesis conducted by a vapor'line, 11', into a heated i caustic'scrubbingltowerA 12. The caustic scrubbing tower, 12, is o f ordinary constructionwith perforatedl trays through which lsa weak solution of caustic sodaor potash passes toward the bottom of the tower. The vapors from thedistilling column, 4, pass through the scrubbing tower` in a streamcounter to 5 that of the warmcaustic solution, the rate of speed withwhich these vapors pass through the -warm caustic solution dependingupon the amount ot heat supplied by the closed steam coil, 8, at thebottom of the column 4. The heat supplied by the closed coil,.

8, is suicient to force all vapors upward into the scrubbing tower. Thevapors introduced into the scrubbing tower are maintained in vapor phaseby heat from a heating coil, 13, arranged inthe jacketof the scrubber,12. As the vaporspass through the warm caustic solution, the sulfurdioxide, polymers, and hydrogen sulfide in the vapors are absorbed bythe caustic forming a bisulfate solution which ows to the bottom of thescrubbing tower and is drawn off. By the time the steam-laden alcoholvapors reach the top o f the scrubbing tower, they are treed fromsubstantially all impurities after which they are conducted into a.second distilling tower 16 through a valve controlled conduit, 14.

v The distilling column,l 16, is the same type as the column still 4,but is provided with a reiluxing coil 18 in the upper portion thereof.Column, 16, is also provided with "a closed steam heating coil, 20, formaintainv ing the desired temperatures in the base of the column. By theuse of the coils, 18 and 20, a deiinite temperature gradient may bemaintained from bottom umn.

The vapor mixture conducted through the pipe, 14, islpreferably,introduced into the mid-portion of column, 16, where thetemrature is suitable for maintaining the butyl and lower boilingalcohols in vapor hase,

and at the same time .permit the con ensation of the amyl and higheralcohols which `are reluxed down through the column and drawn offthrough a pipe 21. A cut temperature is maintained on column, 16,`bymeans of coil, 18, such that the butyl and lower boiling alcohols (withwater) are taken overhead through a. vapor line, 22, condensed in acondenser, 26, and collected in ,a receiver, 28. The alcohols passingvfrom column, 16,

to top of the colthrough pipe, 121, are discharged into a tank, y

24, from which any water present in the mix- `ture 1s withdrawn 'througha valved pipe, 30.

the lower portion of a distilling column 36,

in whichv the mixture is fractionated. The

The alcohols in the mixture in the tank, 24,'

alcohol v column still, 36, is of the as the other two columns, 4, and,16,V hereinbefore described, and is so arranged that the vapors andliquids present therein are in equilibrium at any point of thefcolumnstill, the liquid and vapor at the bottom ot the column still beingricher in less volatilev components than at the top.

The bottom of the column still, 36, is provided with a closed-heatingcoil, 38, through 'which steam is passed to provide suiiicient heat inthe still to eect the desired vaporization of the alcohol mixtureintroduced thereinto. While the alcohol mixture is being in-v troducedinto the still, 36, the-amyl alcohol vapors rise to the top of the stilland pass through a vapor line, 39, into a water cooled condenser, 40, tobe condensed and then How into a trap, 42. Alcohol may from this trapthrough a reiux line 44 int0 the upper part ofthe still, 36, for thepurpose of maintaining the cut temperature therein and alcohol may beconducted through a conduit, 46, to storage tank, 48. n

The amyl alcohol collected in the tank,48, may be dried of any waterthat may have been carried over .during the separation of amyl from thehigher secondary alcohols. During the separation ofthe alcohols,as partof the amyl alcohol flows back into the still,

it tendstovreduce the temperature in the upper portion of the tower. Asa result, the higher alcohols, hexyl, heptyl, etc., arecondensed andreflux toward "the mid-portion of the still and are drawn o by anoutlet,50.

These`higher alcohols may be` separated by,

fractional distillation in the usual manner.

The higher alcohol residues and impurities, such as polymers, are drawnoit from the bottom of the still, 36, by the valved outlet, 52.

The process of the present invention is particularly important from thestandpoint of economy of operation and the purity of the productsobtained, especially when it is realized that the polymers and otherimpurities present in the hydrolyzed kmixture of alkyl sulfates arediiiicultto separate.

Furthermore, by passing alcohol mixtures containing higher and loweralcohols than amyl through a series of fractionating columns asdescribed in this process, the separation of amyl and higher alcoholsfrom butyl and lower alcohols is effected with a shortening of time andan `increase of quantity of alcohols.

The process herein, described for the separation of higherand loweralcohols may be modified without affecting its fundamental principles.Furthermore, the production ot alcohols by a batch or intermittentmethod, or by a plurality kof units of distilling columns operatedcontinuously is contemplated by the present invention.

be conducted y.

same construction l Having described the invention what is claimed asnew is: Y

l. The process of recovering secondary alcohols from a mixture ofhydrolyzed alkyl sulfate which comprises steam distilling a hydrolyzedsolution of-'amyl sulfates containing a mixture of butyl and lowerboiling alcohols, amyl and higher alcohols, free sulfurie acid andimpurities, passing the vapors from said solution through a causticsolution to remove the impurities and into a refluxing and separatingzone in which the butyl and lower boiling alcohol vapors are maintainedin vapor state, passed overhead and condensed, while the amyl and higherboiling alcohol vapors are condensed in said zone and drawn oli" fromthe bottom thereof, sepa-rating the amyl and higher boiling alcoholsfrom any water withdrawn therewith, fractionally distilling theresulting amyl and higher boiling alcohols, and separately col- -lectingthe amyl alcohol from the higher boiling alcohols. y

2. The method of recovering secondary alcohols from a mixture ofhydrolyzed alkyl sulfates which comprises steam distilling a hydrolyzedsolution of alkyl sulfate, passing the resulting steam laden vaporsthrough a warm weak caustic solution to remove impurities and toneutralize 'said va ors, passing the purified vapors into a reflliixingand separating zone whereby the steam laden butyl and lower boilingalcohols are kept in vapor phase, carried overhead and condensed whilethe amyl and higher alcohols arewithdrawn from the bottom of said zone,separated from the condensed water and dry distilled in a third zone,the amyl alcohol coming Aing isobutyl and lower ing secondary alcoholsup to 10 carbon content, sulfuric acid and impurities, passing thevapors through a warm caustic solution to neutralize and purif them,then separatboiling alcohols from amyl and higherboiling alcohols byreiuxing said mixtures, maintaining the butyl and lower boiling alcoholsin vapor phase, collecting overhead and condensing,- while the amyl andhigher boiling alcohols condensed with water are .withdrawn from thebottom of said zone, separated from the water and.

fractionally distilled in another zone, whereby the amyl alcoholswithwater are vaporized, collected overhead and condensed while thehigher boiling alcohols are drawn off at a mid-portion of said zone. y

5. The improvement in alcohol recovery which comprises steam distillinga hydrolyzed alkyl sulfate solution containing a mixture of high and lowboiling alcohols, sulj furic acid and impurities, passing the vaporsthrough weak warm caustic, reuxing and separating the butyl and lowerboiling alcohols fromthe amyl and 4higher alcohols, separating the amylfrom higher boiling alcohols by fractionally distillingand re uxing thehigher alcoholmixture in a separating zone, collecting and condensingthe amyl alcohol overhead while the higher alcohols remaining in saidmixture are drawn off from the mid-portion of said zone.

In testimonyv whereof I aiiix my signature.

4 S. R. MERLEY,

olf overhead while the higher alcohols are drawn oli' at the mid-portionof said zone.

3. The process of recovering secondary alcohols from a mixture ofhydrolyzed alkyl sulfates which comprises steam distilling a hydrolyzedsolution of alkyl sulfates, purifyf .ing and neutralizing the steamdistilled alcohol vapors in a warm caustic solution, passing thepurified .vapors into a vref luxing and separating zone in which thebutyl and lower boiling alcohol vapors remaining in the vapor phase arepassed overhead and 'condensed and collected while the amyl and higheralcohol vapors are condensed in said zone and withdrawn therefrom,separating any water withdrawn therewith, then dry distillin in anotherzone to fractionally separate t e amyl alcohol which is vaporized fromthe mixture of higher alcohols condensed, one part refluxing back intothe zone while the other portion is collected continuously, until allthe amyl is separated from the higher alcohol mixture, the higheralcohols being collected at a midportion of said zone. A

4. The process of recovering secondary alcohols which comprises steamdistilling a solution of hydrolyzedalkyl sulfates contain-

